I am about to go to an informal workshop on naturalism and its implications, organized by cosmologist Sean Carroll. The list of participants is impressive, including Pat Churchland, Jerry Coyne, Richard Dawkins, Dan Dennett, Rebecca Goldstein, Alex Rosenberg, Don Ross and Steven Weinberg. You may have recognized at least four names of people with whom I often disagree, as well as two formerguests of the Rationally Speaking podcast (not to mention Don Ross’ colleague, James Ladyman).

The list of topics to be covered during the discussions is also not for the faint of heart: free will, morality, meaning, purpose, epistemology, emergence, consciousness, evolution and determinism. Unholy crap! So I decided — in partial preparation for the workshop — to start a series of essays on emergence, a much misunderstood concept that will likely be at the center of debate during the gathering, particularly as it relates to its metaphysical quasi-opposite, determinism (with both having obvious implications for most of the other topics, including free will, morality, and consciousness).

It’s a huge topic, and the way I’m going to approach it is to present a series of commentaries on four interesting papers on emergence that have appeared over the course of the last several years in the philosophical (mostly philosophy of physics) literature. Keep in mind that — although I make no mystery of my sympathy for the idea of emergence as well as of my troubles with reductive physicalism — this is just as much a journey of intellectual discovery for me as it will be for most readers. (A good overview can be found, as usual, in the corresponding entry in the Stanford Encyclopedia of Philosophy.)

That said, let us begin with “Emergence, Singularities, and Symmetry Breaking,” by Robert W. Batterman of the University of Western Ontario and the University of Pittsburgh. The paper was published in Foundations of Physics (Vol 41, n. 6, pp. 1031-1050, 2011), but you can find a free downloadable copy of an earlier version here.

Batterman begins by putting things into context and providing a definition of emergent properties: “The idea being that a phenomenon is emergent if its behavior is not reducible to some sort of sum of the behaviors of its parts, if its behavior is not predictable given full knowledge of the behaviors of its parts, and if it is somehow new — most typically this is taken to mean that emergent phenomenon displays causal powers not displayed by any of its parts.” If you think that this amounts to invoking magic, you are not seriously engaging in this discussion, and you may as well save your time and quit reading now.

Batterman sets up his paper on an interesting premise: instead of looking at how philosophers of various stripes have conceptualized emergence and then examining possible cases from the sciences, he goes about it precisely the other way around: “I think it is better to turn the process on its head. We should look to physics and to ‘emergent relations’ between physical theories to get a better idea about what the nature of emergence really is.” This, the attentive reader might have noticed, is just about the same idea of practicing naturalistic (i.e., science-informed) metaphysics proposed by Ladyman and Ross in their Every Thing Must Go, already discussed on this blog and its accompanying podcast.

The second interesting twist in the paper is that Batterman avoids the usual treatment of emergence in terms of mereology, i.e., of parts vs whole. Instead, again bringing Ladyman and Ross to mind, he suggests that the most promising approach to understanding emergence is to look at the mathematical features that play an explanatory role [1] when theories are compared at different energy scales. From then on things become pretty complicated, but I’ll do my best, using extensive quotations from the paper itself.

Batterman takes on an alleged (as it turns out) case of reduction of a phenomenological to a more “fundamental” theory: the relationship between classical thermodynamics (phenomenological) and statistical mechanics (fundamental). The fact is, “the quantities and properties of state in orthodox thermodynamic equations appear largely to be independent of any specific claims about the ultimate constitution of the systems described,” which would seem to cast some doubts on the simple version of the reduction story. As Batterman puts it, “Reduction in this context typically is taken to mean that the laws of thermodynamics (the reduced theory) are derivable from and hence explained by the laws of statistical mechanics (the reducing theory) ... [but] there are very good reasons to deny that all thermodynamic (and hydrodynamic) phenomena are reducible to “fundamental” theory,” and these reasons have to do with phase transitions (solid and liquid, liquid and gas, etc.).

The crucial claim is that phase transitions are qualitative changes that cannot be reduced to fit the more fundamental explanatory principles of statistical mechanics. Phase transitions, therefore, count as genuine emergent phenomena.

The question, of course, is what — then — might explain the qualitative / emergent phenomena. Batterman does not go for the popular, easy but somewhat vacuous, solution of invoking “higher organizing principles.” Instead, he looks toward mathematical singularities in order to get the work done. Let me explain, as far as I understand this.

Batterman directs his reader to the role played by renormalization group theory within the context of condensed matter theory. This is because renormalization theory “provides an explanation for the remarkable similarity in behavior of ‘fluids’ of different molecular constitution when at their respective critical points.” It turns out, experimentally, that there is a universal pattern that describes the behavior of substances of very different micro-constitution, an observation that — suggests Batterman — would make it puzzling if the right explanation were to be found at the lower level of analysis, in terms of the specific micro-constitution of said fluids.

Batterman examines a typical temperature-pressure phase diagram for a generic fluid, and concludes that “Thermodynamically, the qualitative distinction between different states of matter is represented by a singularity in a function (the free energy) characterizing the system’s state.Thus, mathematical singularities in the thermodynamic equations represent qualitative differences in the physical states of the fluid in the container.” The important part here is that the explanatory work is done by mathematical singularities, constructs of which scientists are often wary, indeed — according to Batterman — downright prejudiced against. But prejudice, it turns out, is a poor reason not to bite the bullet and embrace singularities.

Batterman continues: “The renormalization group explanation provides principled physical reasons (reasons grounded in the physics and mathematics of systems in the thermodynamic limit) for ignoring details about the microstructure of the constituents of the fluids. It is, in effect, an argument for why those details are irrelevant for the behavior of interest.” [Italics in the original] In terms of the necessary presence of singularities, Batterman acknowledges that a number of physicists and philosophers consider the appearance of singularities to be a failure of the physical model, but goes on to say: “On the contrary, I’m suggesting that an important lesson from the renormalization group successes is that we rethink the use of models in physics. If we include mathematical features as essential parts of physical modeling then we will see that blowups or singularities are often sources of information.” Singularities are our best friend, insofar as a mathematical understanding of physical processes is concerned.

At the end of the day, of course, both reduction and emergence are necessary, with the latter playing a particular role in the broader picture: “While one may be able to tell detailed (microstructurally dependent) stories about why individual fluids/magnets behave the way they do at criticality [i.e., at the point of phase transitions], such stories simply cannot account for the key property of the emergent protectorates [properties] — namely, their insensitivity to microscopics.”

For Battermann it is downright puzzling that one should always seek explanations at lower levels, even when it it clear that higher level phenomena of a particular class behave uniformly independently of their micro-scale makeup. He asks: “why should that individual derivation [for a particular fluid] have any bearing on a completely different individual derivation for a different fluid with a potentially radically different microstructural constitution?” Why indeed.

At one point Batterman turns the table on the reductionist, essentially accusing him — as I often find myself doing — of ignoring the data in the service of an unjustified a priori preference for a particular ontology: “One crucial and obvious feature of the world is that different things — particles, organisms, etc.— exist or appear at different scales. The world is not scale invariant with respect to space and time.” So why expect that “fundamental” scale-invariant theories should account for all of the world’s features?

Batterman also gets briefly into another example, pertinent to a theory that is arguably the most powerful currently accepted by the physics community, quantum field theory. Despite its spectacular successes, including the incredibly high degree of experimental confirmation, “the theory has been deemed by many to be foundationally suspect. Those who hold that a successful theory should yield predictions from-first-principles, as it were, independent of experimental/phenomenological input believe that it cannot be the final theory. ... more upsetting to many is the fact that quantum field theory when actually used for calculations and predictions typically engenders all kinds of divergences [i.e., mathematical singularities and infinities]. With these monsters ever present, it is claimed that there must be something wrong with the foundations of the theory.” Again, as in the case of phase transitions above, however, it is possible to actually see these “monsters” as the theoretician’s friends, given the amount of explanatory work they actually make possible.

So, the bottom line is that physicists should take singularities and infinities as important — and informative — features of their theories, not as “monsters” indicating underlying flaws in the theoretical architecture. This has happened before in the history of mathematic itself, when Goerg Cantor had a hard time explaining to his colleagues that infinities aren’t mathematically suspect, they are a crucial part of the story. Similarly, the kind of singularity that Batterman is talking about may turn out to be one of the loci of explanation for large classes of emergent properties, as well as a much more solid basis for studying emergence than generic appeals to somewhat mysterious higher organizing principles.

_____

[1] The very idea of mathematics explaining rather than simply quantifying / describing things may sound weird, though it appears to be accepted by many mathematicians and physicists, as well as by philosophers of both disciplines. See, of course, the RS entry on mathematical Platonism and links therein.

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Comments

So the message is that all the guys who somehow achieved publishing success by playing politically correct now slowly sell what others have said before but were rejected and called crackpots for by them?

What you write here, I (and others before me) have said, even down to mentioning thermodynamics as what any consistent underlying statistical physics must come up with regardless the microstructure (thus making thermodynamics in a sense more fundamental than statistical mechanics), in many places, see e.g. Supporting Abstract Relational Space-Time as Fundamental without Doctrinism against Emergence, where I mention this starting on page 5.You academic establishment philosophers rejected this and everything like it and instead demanded to discuss the idiotic Einstein-hole-problem that Einstein already solved.BTW: Singularities are non-physical operationally and show only up in the large number limit. Thermodynamics also works for finite systems. So - surprise surprise - everything you find the most exciting is once again the least insightful part.

Academic "philosophy" = playing the publishing game, exploiting the intellectual upper middle class, making sure reason stays suppressed and history a mere justification of power structures - well done

(A)n informal workshop on naturalism and its implications, organized by cosmologist Sean Carroll. The list of participants is impressive, including Pat Churchland, Jerry Coyne, Richard Dawkins, Dan Dennett, Rebecca Goldstein, Alex Rosenberg, Don Ross and Steven Weinberg...The list of topics to be covered during the discussions is also not for the faint of heart: free will, morality, meaning, purpose, epistemology, emergence, consciousness, evolution and determinism.

Sounds like a fascinating 3 day workshop Massimo and I am really looking forward to watching the videos and reading your essays and articles. The organisers summarised what they will be asking and discussing within those very big subjects as :-

Free will. If people are collections of atoms obeying the laws of physics, is it sensible to say that they make choices?Morality. What is the origin of right and wrong? Are there objective standards?Meaning. Why live? Is there a rational justification for finding meaning in human existence?Purpose. Do teleological concepts play a useful role in our description of natural phenomena?Epistemology. Is science unique as a method for discovering true knowledge?Emergence. Does reductionism provide the best path to understanding complex systems, or do different levels of description have autonomous existence?Consciousness. How do the phenomena of consciousness arise from the collective behavior of inanimate matter?Evolution. Can the ideas of natural selection be usefully extended to areas outside of biology, or can evolution be subsumed within a more general theory of complex systems?Determinism. To what extent is the future determined given quantum uncertainty and chaos theory, and does it matter?

I am however a bit confused as to why this workshop is bringing together a small number of researchers and writers to tackle the project of 'moving naturalism forward' by making progress on these issues, why start the workshop and discussion with a blinkered mentality regarding naturalism and not just try to make progress on these issues regardless?

Most of these questions are self-indulgent crap. Even just looking at the Evolution topic, we've had more involved and detailed discussions over the past week here [of which Sascha has probably made the most significant contributions] than they will even approach at this conference.

Come on Gerhard, its an impressive line up, even Sascha is a fan of Daniel Dennett! If its self-indulgent crap then how come there have been more involved and detailed discussion, with significant contributions over the past week here on several of those subjects and questions? According to your logic Science20 commenters are then also discussing self-indulgent crap!

I agree, it's an impressive lineup, which is why I said this was a performance. I would willingly bet that you will see nothing coming from this conference that you wouldn't have already seen on a half dozen YouTube videos.

What a load of crap. How can this be an impressive lineup? Sascha, father of all thoughts original, king of all scientist, top contributor to sucker2.0, and God's gift to science, is not part of it! NOT PART OF IT, AND NEVER INVITED! That's like a 100 m world championship race with a lineup of crippled, and Usain Bolt watching from the sideline. WHAT MORE PROOF DO WE NEED? All of science and the whole f$&@ing world has turned against Sascha!

Saying that you and Sascha have had more constructive dialogues on evolution than Massimo, Jerry Coyne and Dawkins can have is a bit...much. If those 3 world-class biology PhDs know less than you two about biology, we have a real problem. I do not agree that problem exists.

That isn't actually what I said. They're not discussing evolution. They're discussing whether biocentricism should be extended to include a larger scope ... well that seems to be a rather parochial question. It certainly isn't dependent on being a biologist or much of anything else.

However, if they were going to discuss evolution, I can already see that it won't be much of a discussion without E.O. Wilson or Nowak.

Or take the topic of free will. Really? Hasn't this horse been beat to death enough?

The dialogues that they 'can' have are likely to be substantially different from what they 'will' have.

We should keep in mind that world class Ph.Ds are only human. (Well, one may be questionable.) In any case they have their own load of biases, predilections, and agendas. We can't know from the outset how they will play this.

But they don't have real dialogues they have scripted performances. As new people are constantly coming into the audience they go over the same issues again and again as there is always a market to satisfy. Much of their job is to satisfy this market need, Hamlet is always performed pretty much the same. Such supply and demand always keeps things at about the same level.

Have you read any of their books? What makes you think that they are incapable of any creative thought and that the sponsors are paying to fly them in to talk about...nothing, except be all corporation-y and 'find a market to satisfy'. yet they aren't charging anything and the videos will be online for free.

Yes I have read some of their books, and also a lot of waffle and inane rubbish that doesn't say anything original. Some definitely are capable of creative thought but that doesn't seem to be where it happens. Sure their videos are free, thats not the point. They are still filling a niche, meeting a market need just not getting the cash immediately. There are millions of people who don't want the best that is on offer because it is too difficult to get your head around in a short amount of time and because they don't want to know the answers. "Free will" is a classic, no answer as to what it "is" is ever going to be good enough because people don't want an answer. They want to believe something is "really free". If that many people want something, someone will provide it and the highest authority figures will be most sought because of their status. Traditional religion used to do this.

Reading Massimo's post last night stirred a a surprising impulse in me. I went looking for a reference to a group that a friend told me about a couple of years who which is exploring new ways to think about evolution. So I went looking for the "Alternberg 16" and as it turns out Massimo was the instigator of that misunderstood group; the creationists are having a field day with it which is a pain in the ass. Susan Mazur be damned! Methinks I must now become a Jungian. :)Before we go running off condemning this as just another talk fest perhaps per chance we should find out what they are on about? In case peoples' memories are in disorder it might be useful to recall that at Copenhagen many physicists did wander about discussing their ideas and slowly but surely creating a new way of understanding what is going on out there. The new synthesis has to start somewhere.

My interest is more molecular in that I am still trying to find developments in the ideas about the implications of geometry with regard to biological processes. This theme goes way back to 1927 - The Shape of Life, Goodwin, and in recent decades has slowly but surely garnered more attention from mathematical biologists. It has always been clear to me that resorting to the typical analytic approach in molecular biology that relies on physics and chemistry is incomplete, not enough, so I welcome any further developments that can help us gain a deeper understanding.

I am not happy with the modern synthesis so I hope Massimo and his crowd can help develop an extended modern synthesis. As one wit commented: new ideas are like seedings - easily crushed. So tread carefully.

Massimo, do you mind explaining why you are not allowing comments on your 'Essays of Emergence Part II'? I like to hear different viewpoints discussing the subjects you are covering, don't most people?

Why all this griping? As soon as anyone mentions emergence, an elephant marches into the room and parks its ass on the dining table. The name of the elephant is Consciousness. It is the ultimate question about emergence, and we know nothing - nothing! - about it. More talk (e.g., the naturalism workshop) may not change that. Not talking will definitely not change it.